Everything you need to know about Genetics… You can learn from your Cat! BY
DR. LESLIE LYONS
College of Veterinary Medicine, University of Missouri
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THE GENETICS OF CATS EYES… …THE WINDOWS TO THEIR SOULS The genetics of eye color in cats has not been formally investigated. However, since cats are mammals and 90% of genes are shared between humans and cats, we can glean information from human studies to help infer what may be influencing eye color in cats. Some structures and functions of cat eyes are different from humans. The muscles in the cat’s iris can change the pupil from round to a narrow horizontal slit. The tapetum lucidum, a reflective layer behind the retina, increases the amount of light for night vision in many nocturnal vertebrates. These differences from the human eye are due to a cat’s vision being highly adapted for their survival as nocturnal predators within their ecological niches. Although humans and cats have different but now overlapping niches, eye color has been under artificial selection by breeders and less natural selection by the niche. The iris and eye color
EDITOR: This is the Seventeenth article in a series based on feline genetics by Dr Leslie Lyons being published in FELIS HISTORICA during the 2020/2022 period Article Graphics ©www.gograph.com
The color of the eye is caused by the same cells that produce color in the skin and fur, melanocytes, which are also present in the iris.1 The iris is the colored part of the eye that contains muscles, which control the size of the pupil, hence, the amount of light that enters into the eye. Light passes through the pupil, through the lens to the back of the eye where the cells of the retina process the light and image. The iris has two tissue layers, both having melanocytes, however, the types of pigments produced in each layer are different. The two layers are the anterior stromal layer and the posterior epithelial layer, which are each derived from different embryonic tissues therefore, the layers have different origins of development.